A. Field of the Invention
Embodiments of the invention relate to semiconductor devices and, in particular, to semiconductor devices used with wiring terminals.
B. Description of the Related Art
In an apparatus such as an inverter apparatus, an uninterruptible power supply, a machine tool, and an industrial robot, a semiconductor device (general-purpose module), including power semiconductor elements mounted therein, is used independently of a main body of the apparatus. Such a semiconductor device can have a structure in which a plurality of power semiconductor elements is sealed (packaged) in a resin case. Internal wiring of such a semiconductor device is generally realized by wiring terminals (lead frames).
FIG. 11 is a configuration view illustrating main parts of a semiconductor device of the related art, including a power semiconductor element packaged in a resin case. FIG. 11 illustrates an example of a semiconductor device in which internal wiring is realized by wiring terminals. In the semiconductor device illustrated in FIG. 11, an Insulated Gate Bipolar Transistor (IGBT) device 501 is disposed in a resin case 503. Here, the IGBT element 501 is a vertical power semiconductor element in which an emitter electrode is provided on the upper surface thereof and a collector electrode is provided on the lower surface thereof (not shown). The emitter electrode of the IGBT element 501 is electrically connected to a wiring substrate 502 through a wiring terminal 504. The collector electrode of the IGBT element 501 is electrically connected to the wiring substrate 502 through direct contact.
The bonding between the wiring terminal 504 and the emitter electrode and between the wiring terminal 504 and the wiring substrate 502 is generally realized, for example, by soldering, ultrasonic bonding, or laser welding. An example of such a semiconductor device of the related art is disclosed in Japanese Patent Application No. 2009-141000 (also referred to herein as “Patent Literature 1”), for example. Next, a semiconductor device of the related art disclosed in Patent Literature 1 will be described in detail with reference to FIG. 12.
FIGS. 12A and 12B are configuration views illustrating a semiconductor device of the related art. FIG. 12A is a plan view of main parts of a semiconductor device 500. FIG. 12B is a cross-sectional view of main parts taken along the line X-X in FIG. 12A as viewed from the direction indicated by arrows. FIGS. 12A and 12B illustrate an example of a semiconductor module corresponding to one phase of an inverter circuit.
A semiconductor device 500 illustrated in FIGS. 12A and 12B includes a plurality of external connection terminals 53, 54, 55, 56, 57, and 58 that is fixed and supported on a resin case 63, IGBT elements 51a and 51b and Free Wheeling Diode (FWD) devices 52a and 52b that are packaged in the resin case 63, and a terminal block 60 in which wiring terminals 59 are disposed so as to electrically connect these semiconductor elements to any one of the external connection terminals 53, 54, 55, 56, 57, and 58. The wiring terminals 59 are connected to the IGBT elements 51a and 51b and the FWD elements 52a and 52b through terminal holders 61. The emitter electrodes of the IGBT elements 51a and 51b are connected to the anode electrodes of the FWD elements 52a and 52b by terminals 62a and 62b, respectively. With this configuration, the layout of the wiring terminals 59 in the resin case 63 of the semiconductor device 500 in which a plurality of semiconductor elements is packaged in the resin case 63 can be changed easily. By changing the layout of the wiring terminals 59, the external connection terminals 53, 54, 55, 56, 57, and 58 which will be used actually can be selected (see, for example, Patent Literature 1).
As another apparatus, a semiconductor device (module) is disclosed in which a lid having a nut holder that holds a nut provided on the upper surface of a case includes a lid chassis unit and a lid cartridge unit which are separated from each other. In this semiconductor device, by preparing lid cartridge units having nut holders corresponding to various nut dimensions and exchanging the lid cartridge units, it is possible to change an attachment nut so as to meet the specifications of users. See, for example, Japanese Patent Application No. 2009-81255 (also referred to herein as “Patent Literature 2”).
As still another apparatus, the following semiconductor device is disclosed. A mounting substrate is bonded to a radiator plate. The mounting substrate has conductor patterns on both surfaces thereof. A semiconductor chip is soldered to the surface of a base conductor. A thin wire electrode group is in contact with the emitter electrode of the semiconductor chip. A probe holder brings spherical contact portions of the thin wire electrode group attached in parallel to an attachment board into pressure-contact with the emitter electrode. The thin wire electrode group is inserted into and held by the insulating probe holder, whereby the contact pressure in relation to the emitter electrode is set. The probe holder is held appropriately by a collector lead-out conductor and a supporting conductor and sealed in a resin case using a terminal capacitor. With such a structure, a semiconductor device exhibits excellent power cycling performance and thermal fatigue properties. This semiconductor device has a structure in which main terminals protrude from the central part of a lid (terminal capacitor) that covers the resin case. See, for example, Japanese Patent Application No. JP-A No. 10-256319 (also referred to herein as “Patent Literature 3”).
As still another apparatus, a semiconductor device is disclosed in which a semiconductor chip is fixed to a U-shaped electrode portion, main terminals are connected to the U-shaped electrode portion, and the main terminals protrude from the central portion of the ceiling of a resin case. The U-shaped electrode portion is interposed between the semiconductor chip and the main terminals to thereby improve mechanical strength and reduce thermal stress applied to the semiconductor chip. See. for example, Japanese Patent Application No. JP-A No. 6-188335 (also referred to herein as “Patent Literature 4”).
However, the techniques disclosed in Patent Literatures 1 to 4 have the following problems. In the semiconductor device 500 disclosed in Patent Literature 1, the wiring terminals 59 are connected to the terminal holders 61 disposed at the central part of the resin case 63. The terminal holders 61 are locations to which AC outputs of an inverter circuit, for example, are output. Thus, the positions of the external connection terminals 56 and 58 of the main terminals serving as the AC output terminals, for example, can be easily changed by changing the terminal block 60. In contrast, the external connection terminals 54 and 57 including a P terminal and a N terminal which are the main terminals of an inverter circuit are fixed to an insulating substrate 64 in the resin case 63 through a connection terminal 65. Thus, in order to change the positions of the external connection terminals 54 and 57, it is necessary to change the positions in each resin case 63. Thus, the change of the external connection terminals is not typically easy to perform.
In the techniques disclosed in Patent Literatures 2 to 4, in any of the semiconductor devices, although the main terminals are disposed at the central part, the main terminals are fixed directly to the semiconductor element. Thus, it is typically not easy to change the positions of the external connection terminals which are the main terminals.
Thus, there is a need in the art to address the above-described problems in the art.